1. Field of the Invention
The present invention relates to an ink jet recording apparatus having an ink jet head for use in the recording or printing (hereinafter referred to as xe2x80x9crecordingxe2x80x9d) of characters, symbols or images (hereinafter typically referred to as xe2x80x9cimagexe2x80x9d) by discharging the ink or functional liquid (hereinafter typically referred to as xe2x80x9cinkxe2x80x9d) onto the recording carrier such as the paper, plastic sheet, cloth, article and so on (hereinafter typically referred to as xe2x80x9cpaperxe2x80x9d), or an ink jet pen containing an ink reservoir for reserving the ink to be supplied to the ink jet head. This invention also relates to an operation method for the ink jet apparatus.
By the ink jet pen as herein used is meant encompassing both the cartridge form having an ink jet head and an ink reservoir integrally provided and the form having them separately provided to be detachable. This ink jet pen can be freely attached to or detached from mounting means such as a carriage on the main unit of the apparatus. Also, by the ink jet apparatus as herein used is meant encompassing a variety of forms including those integrally or separately provided as the output terminal for the information processing equipment such as a word processor or a computer, a copying machine combined with an information reader, a facsimile apparatus having the information transmission or reception feature, and a machine for the textile printing onto the cloth.
2. Related Background Art
In the ink jet recording apparatus, when the apparatus is not used for a long time, the water content or other volatile components within the nozzles (hereinafter also referred to as xe2x80x9cdischarge orificesxe2x80x9d) may vaporize to cause the viscosity of the ink to increase or bubbles to mix into the nozzles or ink flow passageways, thereby impeding the ink from being excellently discharged. In order to recover such ink condition to original excellent condition for the ink discharge, the ink jet recording apparatus is often provided with some recovery means. One example of such recovery means may include a suction mechanism for sucking the ink from the nozzles when a cap covers the nozzles, and supplying the new ink from an ink tank to a head. Typical elements constituting such suction mechanism include a cylinder pump for generating pressure changes by the use of the relative movement between the cylinder and the piston, and a tube pump for generating pressure changes by stroking the tube.
In such ink jet recording apparatus, it was apprehended that if the ink dries inside of a suction mechanism, that is, inside of a cap, a pump, an ink suction passageway leading from the cap to the pump, or a waste ink flow passageway leading from the pump to a waste ink reservoir, the dried ink may cause an inconvenience of blocking the flow of the ink. For example, it was apprehended that if the ink solidifies within the pump, the pump may be possibly stopped. Or it was apprehended that the ink solidifies inside the waste ink flow passageway and is impeded from flowing, though the ink is essentially directed into the waste ink reservoir, so that the ink is reversely flowed to the head side to make worse the discharge characteristics, thereby having adverse effect on the recording quality, or the ink will overflow from unexpected portion into the apparatus to contaminate the apparatus inside or have detrimental effect on the electric circuit within the apparatus.
Such problems also exist on the side of the ink jet head. For example, a typical example of the ink jet pen as previously described includes a form in which an ink jet head and an ink reservoir for reserving the ink to be supplied to the head are integrated together detachably. The ink jet head is provided with discharge orifices for discharging the ink, and also electrothermal converters to generate the heat energy, for example, as the energy used to discharge the ink from the discharge orifices. The ink reservoir mostly contains a porous absorbing member for reserving the ink. The ink supply passageway for communicating the ink jet head to the ink reservoir is commonly provided with a filter to trap the foreign matter such as dirt in the ink.
In the use of such ink jet pen, when the ink reservoir was not attached to the ink jet head for a long time, it occurred that ink components vaporized from the filter portion of ink supply passageway or discharge orifices to cause the ink to solidify and be fixed to the wall surface of ink passageway. There was a problem that once such ink fixing occurs, the supply of the ink is impeded by fixed ink and the discharge of the ink becomes bad even if the ink reservoir is attached again to the ink jet head.
The above-mentioned technical problem is more remarkable in the case of using the waterproof ink which becomes water insoluble after drying. The waterproof ink which becomes water insoluble after drying can meet a recent technical demand of improving the waterproofness of recorded image, but on the other hand, has brought about a new technical problem that the ink is more likely to fix in the interior of the apparatus. That is, this is a technical problem that such waterproof ink is liable to fixing in the interior of the recovery mechanism or the ink passageways of the ink jet head.
An object of the invention is to resolve the aforementioned technical problem, and to provide an ink jet apparatus and its operation method which is capable of maintaining the stable recording condition for the long term, because the ink fixing does not occur in the ink channels or can be removed promptly, even if it occurs.
It is another object of the invention to provide an ink jet apparatus and its operation method which is capable of maintaining the stable recording condition for the long term, because the ink fixing does not occur in the interior of a recovery mechanism or can be removed promptly, even if it occurs.
It is a further object of the invention to provide an ink jet apparatus and its operation method, wherein the ink fixing does not occur in the interior of a recovery mechanism for recovering an ink jet head using the waterproof inks of which at least one ink becomes water insoluble after drying, or can be removed promptly, if it occurs.
It is a still further object of the invention to provide a color ink jet apparatus and its operation method, wherein the ink fixing does not occur in the interior of a recovery mechanism for recovering an ink jet head using the waterproof inks of which at least one color ink becomes water insoluble after drying, or can be removed promptly, if it occurs, and wherein the color mixing is less likely to occur.
It is a yet further object of the invention to provide an ink jet apparatus and its operation method wherein even when an ink reservoir is not attached for a long time to an ink jet head using the waterproof ink which becomes water insoluble after drying, the ink fixing is less likely to occur in the ink passageways for the ink jet head, and the stable ink discharging is enabled immediately after attaching the ink reservoir.
It is another object of the invention to provide an operation method for an ink jet recording apparatus comprising a cap for covering the discharge orifices for discharging the ink, and suction means for effecting suction through said discharge orifices when said cap covers said discharge orifices, characterized by including in sequence:
a suction process of effecting suction through said discharge orifices by driving said suction means when said cap covers said discharge orifices;
a discharge process of discharging the ink from said discharge orifices into said cap; and
an exhausting process of exhausting the ink out of said cap.
It is another object of the invention to provide an operation method for an ink jet apparatus mounting an ink jet head provided with the discharge orifices for discharging the waterproof ink which becomes water insoluble after drying, and an ink reservoir for reserving said ink to be supplied to said ink jet head, characterized by including an exhausting process for exhausting said ink out of said ink jet head when said ink reservoir is attached.
It is another object of the invention to provide an ink jet apparatus characterized by comprising:
a cap for covering the discharge orifices for discharging the ink;
suction means for effecting suction from said discharge orifices when said cap covers said discharge orifices; and
control means for making the control to effect suction from said discharge orifices by driving said suction means when said cap covers said discharge orifices, and discharge the ink from said discharge orifices into said cap to exhaust the ink cut of said cap.
It is another object of the invention to provide an ink jet apparatus having:
an ink jet head provided with the discharge orifices for discharging the waterproof ink which becomes water insoluble after drying;
an ink reservoir for reserving said ink to be supplied to said ink jet head; and
control means for making the control to exhaust said ink out of said ink jet head when said ink reservoir is not attached.
The present invention has been achieved as a result of the careful researches by the present inventors to resolve the above-mentioned technical problem which is the fixing of the ink in the interior of the recovery mechanism, and especially a more remarkable technical problem which arises in the case of using the waterproof ink which becomes water insoluble after drying. That is, the present invention resides in preventing or removing the ink fixing within the recovery mechanism containing a cap by predischarging the ink into the interior of the cap after performing suction recovery via the cap, and thereafter evacuating the ink itself having caused the ink fixing from the inside of the recovery mechanism by exhausting the ink remaining inside the recovery mechanism by idle suction. In this case, with an ink jet apparatus using both the waterproof ink which becomes water insoluble after drying and the normal non-waterproof ink, even if the ink fixing occurs due to the waterproof ink, the non-waterproof ink will mix therein by predischarge, whereby the effects of the present invention of preventing or removing the ink fixing can be more remarkably exhibited.
Also, if using the inks of different colors as the waterproof ink which becomes water insoluble after drying and the normal non-waterproof ink, suction is performed via a cap collectively covering the discharge orifices for discharging the inks, the inks of different colors may be mixed within the cap, and reversely flowed into the discharge orifices, resulting in a technical problem of color mixing. However, according to the present invention, the technical problem of color mixing can be also resolved, because mixed color inks can be exhausted out of each discharge orifice by predischarging after suction.
According to the present invention, even when an ink reservoir is not attached for a long time to an ink jet head using the waterproof ink which becomes water insoluble after drying, the ink within the ink jet head can be exhausted, and therefore the ink fixing is less likely to occur in the ink passageways of the ink jet head, and the stable ink discharge is enabled immediately after attaching the ink reservoir.
By xe2x80x9csuctionxe2x80x9d as herein used is meant that when the cap covers the discharge orifices, suction is performed via the cap from the discharge orifices by driving suction means represented by a pump. By xe2x80x9cidle suctionxe2x80x9d as herein used is meant that when the cap opens the discharge orifices, or when the cap inside is communicating to the atmosphere by opening a valve in communication with the cap even if the cap covers the discharge orifices, suction is performed to draw the air into the inside of the recovery mechanism via the cap by driving suction means represented by the pump. Exhausted ink is finally conducted into a waste ink reservoir provided within the main unit, for example, and held not to leak outside. By xe2x80x9cpredischargexe2x80x9d as herein used is meant to perform the ink discharging into ink receiving means such as a cap, irrespective of the recording. By xe2x80x9cwipingxe2x80x9d as herein used is meant wiping out by a wiper blade normally made of an elastic material the foreign matter such as ink droplets or dirt adhering to the discharge orifice face on which discharge orifices of the ink jet head are provided.
Thus, according to the present invention, it is possible to resolve the above-described technical problem of ink fixing in the interior of the recovery mechanism, and especially a more remarkable technical problem when the waterproof ink which becomes water insoluble after drying is used.
Also, according to the present invention, since even when the color recording is performed, the mixed color inks can be exhausted out of each discharge orifice by predischarging after suction, the technical problem of color mixing can be resolved.
Further, according to the present invention, since even when an ink reservoir is not attached for a long time to an ink jet head using the waterproof ink which becomes water insoluble after drying, the ink within the ink jet head can be exhausted, the ink fixing is less likely to occur in the ink passageways of the ink jet head, and the stable ink discharge is enabled immediately after attaching the ink reservoir.
The above and other objects, effects, features, and advantages of the present invention will become more apparatus from the following description of embodiments thereof taken in conjunction with the accompanying drawings.